Grand noria of Fez al-Jadīd

While the topography of the city of Fez meant that water could be supplied from the river by gravity alone, it became necessary to use water elevation methods to supply water to those places on higher ground. The most effective system at this time consisted of the vertical wheels fitted with pails on their rims. These systems had the advantage of being driven by the river’s current, which guaranteed a continuous movement. The people of Fez described them as nā‘ūra (noria). The first historical evidence of a wheel existing at Fez appeared as the term dūlāb, a word with Persian origins (dūl means bucket, and āb, water). Indeed, Ibn al-Khatīb (d. 1374) reported in his work al-Ihāta that Ibn al-Hājj, from Sevilla and connoisseur of mechanical systems (al-hiyal al-handasiyya), had a very impressive hydraulic wheel (dūlāb) constructed at Fez al-Jadīd, on the request of the Marinid sovereign Abū Yūsuf al-Mansūr: ‘it is [he says] large in diameter, and its range and circumference are considerable: it has a large number of buckets, and its movement is mysterious, so much so that this monument attracts the visitors’ attention.’

It would seem that this hydraulic wheel was very large. This would indicate that the help of this ‘engineer’ from the Mediterranean’s ‘other shore’ was not enlisted to introduce this technique for the first time in Morocco but rather to create a unique and spectacular machine. In fact, this wheel was designed to raise water to the level of the Marinid aqueduct that supplied the royal garden of al-Mosāra. Nothing remains of the wheel, but there are traces several centimetres deep and around thirty centimetres wide engraved by friction of its rim on the two sides of the ditch. The wheel plunged into the Wadi, which was probably 3m deep at this point, and only the upper half of this enormous wheel would have been visible.

The elevating wheel’s dimensions were exceptional, and a real technical feat. The largest norias, for example, those at Hama (Syria), had a maximum diameter of 21m. Dimensions as large as these require great technical know-how. M. Michaux-Bellaire has revealed that this wheel was made of copper, or rather wood covered in copper, which may explain the name of Burj al-Nuhās (the Copper Tower) given to a nearby tower.

The correct working of this original structure required that ‘the engineer’ Ibn al-Hājj set the balance of the wheel (central weight) and guarantee an excellent distribution of internal forces during its movement. It was also necessary to resolve, elegantly, the problems related to rigidity and the cohesion of all the parts of the wheel, and at the same time ensure the flatness and circularity of the wheel. The other difficulty lay in obtaining pieces of wood large enough to make the wheel’s arms in several segments.

While there is no existing literature that describes the techniques for making this noria and its assembly techniques, we do possess, several pieces of evidence that attest to the existence of a corporation of craftsmen (nwā‘riyya) responsible for constructing this type of hydraulic structure, as well as illustrations of noria, like that in the Bayad wa Riyad manuscript[2].